The present invention relates to an escalator or a moving walkway which is self-supporting over certain regions.
In connection with statics calculations for escalators, consideration must be given to vertical framework oscillations which can be excited by chain engagement (resonant oscillations). When safety factors are applied, due to the sensitivity of the framework oscillation system relatively large forbidden regions result, particularly in the case of moving walkways with equal bay divisions. In the case of escalators with unequal bay divisions, these regions may be even larger due to the nature of safety factor computation and application. For these reasons only relatively small bay widths are often available.
It is the object of the present invention to eliminate restrictions on available bay widths by providing an escalator with the capacity to control framework oscillations.
According to the invention this object is met by an escalator of the kind stated in the introduction in that for reduction of externally-excited oscillations there is provided an oscillation damper which is connected with the escalator or moving walkway within a self-supporting region, preferably at the point of the greatest displacement due to the oscillations.
According to the invention there is thus provided an oscillation damper which damps the resonant oscillationsxe2x80x94should they occurxe2x80x94so that they no longer need to be taken into consideration in statics calculations. In this manner greater bay widths can be realised.
The oscillation damper is preferably a speed-proportional plate damper comprising plates which move relative to one another in viscous oil. Since the oscillations to be damped have only very small amplitude, a powerful damper is needed. Such a speed-proportional plate damper is suitable for this purpose.